Every January, die-hard fans gather in Parkes, Australia to celebrate the birthday of the King of Rock 'n' Roll.

PARKES, Australia—Elias Jamhour has a problem. He's bigger than Elvis.

Or at least that's the case on a train departing Sydney for one of the unlikeliest Elvis festivals on the planet.

As the tribute artist gyrates through the carriages on a seven-hour journey into the Australian countryside, the attentions of his fans—many of whom wear badges declaring "Elias 4 Elvis" and "I-heart-Elias"—becomes...